1.
[syn: collaborator, cooperator, partner, pardner]
The Collaborative International Dictionary of English v.0.48:
Cooperator \Co*["o]p"er*a`tor\, n. [L.: cf. F. coop['e]rateur.]
One who labors jointly with others to promote the same end.
"Cooperators with the truth." --Boyle.
[1913 Webster]
WordNet (r) 3.0 (2006):
cooperator
n 1: an associate in an activity or endeavor or sphere of common
interest; "the musician and the librettist were
collaborators"; "sexual partners" [syn: collaborator,
cooperator, partner, pardner]